Such propellers are usually formed from a plurality of propeller blades each being located by a radially inner end, called a shank, in a barrel of a hub of the propeller. Conventionally, the hub is made in separable halves to allow insertion of bearings between races on the shank and races on the hub. These bearings permit rotation of the blade in the hub to vary the pitch of the propeller.
EP 0322344 discloses a one-piece hub arrangement in which the shank of a propeller blade is inserted into a barrel of the hub. Bearings are fed between the barrel and the shank until they are positioned between races provided by the shank and barrel. The bearings are pre-loaded by outwards movement of a race insert in threaded engagement with the hub barrel. Such a method is complicated and time consuming. Further, the use of threads in the hub barrel can lead to failure of the assembly.
The inner bearing of EP 0322344 also provides the means for retaining the blade within the hub by acting against an inner race provided by an inwardly extending portion of the barrel wall. This portion is integrally formed in order to avoid discontinuities.